ad7705.c

原创：用C51编写的关于数模转换器AD7705的读写程序

/*----------------AD7705------------------*/
void select7705(uchar partnumber)
{
   switch(partnumber)
   {
     case 1:PA18155=PA18155&0xfd;break;
     case 2:PA18155=PA18155&0xf7;break;
     default:break;
   }
}

void unselect7705(void)
{
   PA18155=PA18155|0x0f;
}

void write_bit7705(uchar w_bit)
{
  if(w_bit==0)
    DIN7705=0;
  else
    DIN7705=1;
  SCLK7705=0;
  SCLK7705=1;
}

uchar read_bit7705(void)
{
  uchar r_bit;
  SCLK7705=0;
  SCLK7705=1;
  if(DOUT7705==0)
    r_bit=0x00;
  else
    r_bit=0x80;
  return(r_bit);
}

void write_part7705(uchar w_data)
{
  uchar index;
  uchar param;
  SCLK7705=1;
  for (index = 0; index<8; index++) /* Write out data */
  {
    param = w_data<<index;
    param &= 0x80;
    write_bit7705(param);
  }
}

uchar read_part7705(void)
{
  uchar index;
  uchar r_data=0;
  SCLK7705=1;
  for (index = 0; index<8; index++) /* Write out data */
  {
    r_data |= read_bit7705()>>index;
  }
  return(r_data);
}

void wait7705(uchar channel)
{
  do{
      write_part7705(channel | 0x08);
    }while(read_part7705()&0x80);
}

int ad7705(uchar partnumber,uchar channel)
{
  uchar i,hi_data,lo_data;
  uint  all_data;
  ulong total_data;
  int  sample_mv;
  total_data=0;
  select7705(partnumber);
  wait7705(channel);
  write_part7705(channel | 0x38);
  hi_data=read_part7705();
  lo_data=read_part7705();
  for(i=0;i<8;i++)
  {
    dog();
    wait7705(channel);
    write_part7705(channel | 0x38);
    hi_data=read_part7705();
    lo_data=read_part7705();
    all_data=hi_data;
    all_data=(all_data<<8)|lo_data;
    total_data=total_data+all_data;
  }
  sample_mv=(int)((total_data>>3)-32768);
  unselect7705();
  return(sample_mv);
}

void ad7705s(uchar mode,uchar partnumber,uchar channel)
{
   uchar i;
   uchar j;
   dog();
   select7705(partnumber);
   write_part7705(channel | 0x20);
   write_part7705(0x0c);
   write_part7705(channel | 0x10);
   write_part7705(mode);
   wait7705(channel);
   write_part7705(channel | 0x60);
   j=(partnumber-1)*3+channel*3;
   for(i=0;i<3;i++)
   {
     write_part7705(ad7705jzdata[j+i]);
   }
   unselect7705();
}

void ad7705z(uchar mode,uchar partnumber,uchar channel,uchar x,uchar y)
{
   uchar i;
   uchar j;
   uchar m;
   dog();
   select7705(partnumber);
   write_part7705(channel | 0x10);
   write_part7705(mode);
   wait7705(channel);
   write_part7705(channel | 0x68);
   for(i=0;i<3;i++)
   {
     m=read_part7705();
     j=x+i*0x06;
     showys(m,j,y,1);
   }
   unselect7705();
}
/*----------------AD7705------------------*/